/Engine/Source/Runtime/Engine/Classes/Materials/Material.h
virtual FGraphEventArray PrecachePSOs ( const FPSOPrecacheVertexFactoryDataList & VertexFactoryDataList, const [FPSOPrecacheParams](API\Runtime\Engine\FPSOPrecacheParams) & PreCacheParams, EPSOPrecachePriority Priority, [TArray](API\Runtime\Core\Containers\TArray)< FMaterialPSOPrecacheRequestID > & OutMaterialPSORequestIDs )